I feel like I can relate somewhat to this.
I've recently been having these intense fears that are somewhat similar to yours, although they are not identical... but I can describe a tiny bit and then tell you what I am doing. Basically I am fearful of not only my self existing but of anything existing at all? I feel fearful that I am stuck in the universe and stuck being alive and there is nowhere else to go or other way to exist. Even if I were to die, I still would have been alive here at some point. When I get anxiety about this it makes my perspective feel very awkward anywhere I go, like I am just floating and like objects are moving to me and I'm still in the same place rather than moving through a 3d world with depth. I feel really freaked out that I can feel my body sitting in the room, that I can experience what is happening, etc. because it just does not make sense how anything is possible to me. I definitely feel "hyper-sensitive" as well, and the sense of touch is the worst. It feels like my skin is vibrating everywhere and I can't stop thinking of how weird it is that I can feel things touching my skin. I mean I know a lot about physics and a little biology and plenty of other stuff to logically understand the world - but there is this underlying: "Why? Why is there anything at all? Why am I alive and experiencing this world? Why is it the way it is and not completely different?" that never gets answered of course. It's given me several panic attacks in the last few weeks, because I get freaked out that I'm here and myself and there's nowhere I can escape to or nothing else I can be. It's really hard to describe so who knows if it's really that similar or not. I'm sure what you experience is very hard to describe as well.
So, uhm, what helps me feel a little better at least (other than trying to distract myself by doing random activities) is to really question exactly why there is something to be afraid of? I usually don't ask myself this question directly, because I'll just think of endless amounts of answers, but ask something like: "What would it take for a computer AI program simulating a human to become afraid of its own existence / of existence itself?" - And then I come up with the answer that there has to be a programmed response of fear to certain thoughts or perceptions, such as a fear of being trapped, which would make sense as something that happens within humans that has developed through evolution. And then I think: "okay, it makes sense that my body has a fearful response to feeling trapped, and I feel trapped in my self existence so my body is just responding to that."... Then I just try to keep telling myself that... the feelings of fear and anxiety are simply my body responding to what it thinks is a danger (being in the universe / in my own perspective), but that it's not really something to be afraid of. I tell myself that if I were to think of it objectively without a body that has chemical reactions happening, there would be no fear. I may not understand it, but there would be nothing to cause a fearful response about it, and that's the part that's really bad.
Another thing I've done was during one moment of feeling pretty back to normal (between episodes of high anxiety), I wrote a note to my future self telling me how it was still possible for me to feel normal, and how in my normal state I could think about all the things I think of during times of high anxiety and not feel bad. Again, might be confused but it would be okay because my body wasn't having any strange responses to my thoughts during that time. So then, later, I was able to look at this note again as proof that it was possible to not be fearful while having the same thoughts, and thus proof that it's not the nature of the thoughts themselves that causes fear, but simply how my body is reacting at certain times.
Anyway, maybe you could think something like that. It doesn't always help me and it isn't perfect as a solution but I've had less panic attacks since I've told myself that. I still feel pretty strange most of the time because of some unusual realization that I'm really here, sitting in my room, in this only universe, and this moment will never happen again, etc. But thinking the above thoughts helps me feel like it's okay. Benzos help too (I have some xanax) but only after the anxiety is triggered, it doesn't make the source any less potent of course.
I hope this helps some.